JP5952812B2 - Primer composition and adhesive tape - Google Patents

Description

  The present invention relates to a primer composition interposed between a film substrate of an adhesive tape and an adhesive layer, and an adhesive tape using the primer composition.

Known primer compositions for pressure-sensitive adhesive tapes include graft polymers obtained by graft polymerization of methyl methacrylate on natural rubber, and those obtained by adding acrylonitrile butadiene rubber thereto (for example, Patent Document 1). And Patent Document 2).
Furthermore, a primer composition interposed between the film base material of the pressure-sensitive adhesive tape and the pressure-sensitive adhesive layer that improves the adhesion between the film base material of the pressure-sensitive adhesive tape and the pressure-sensitive adhesive layer is desired.

JP 2001-302965 A JP 2002-146274 A

  The present invention uses a primer composition that improves the adhesion between the film substrate of the pressure-sensitive adhesive tape and the pressure-sensitive adhesive layer, interposed between the film base material of the pressure-sensitive adhesive tape and the pressure-sensitive adhesive layer, and this primer composition. It is an object to provide an adhesive tape.

This invention is provided in order to solve the said subject, and is an invention concerning the following [1]-[6].
[1] It has 100 parts by mass (in terms of solid content) of a graft polymer obtained by graft polymerization of 15 to 65% by mass of methyl methacrylate on natural rubber, and 25 to 300 parts by mass of carboxyl group-modified acrylonitrile butadiene rubber. Primer composition.
[2] The primer composition contains MS _{1 + 4} , graft polymer of Mooney viscosity 70 to 160 at 100 ° C., or 100 parts by mass (in terms of solid content) of the graft polymer. The primer composition according to [1], further comprising 0.1 to 10 parts by mass (in terms of solid content) of a surfactant.
[3] The primer composition according to [1] or [2], wherein the carboxyl group-modified acrylonitrile butadiene rubber in the primer composition has a carboxyl group modification amount of 0.3 to 7% by mass. .
[4] The above-mentioned [1] to [3], wherein the graft polymer in the primer composition is obtained by graft polymerization of natural rubber and 30 to 50% by mass of methyl methacrylate. The primer composition according to any one of the above.

[5] A natural rubber in which any one of the above primer compositions [1] to [4] is laminated on at least one surface of a film base material mainly composed of soft polyvinyl chloride. A pressure-sensitive adhesive tape obtained by interposing between a pressure-sensitive adhesive layer mainly composed of
[6] The pressure-sensitive adhesive tape according to [5], wherein the pressure-sensitive adhesive tape is for electrical insulation.

  The primer composition of this invention can improve the adhesiveness of the film base material and adhesive layer of an adhesive tape.

The primer composition of the present invention comprises a graft polymer obtained by graft polymerization of 15 to 65% by mass of methyl methacrylate on natural rubber (hereinafter also referred to as “graft polymer”), and a carboxyl group-modified acrylonitrile butadiene rubber (hereinafter referred to as “ Also referred to as “modified NBR”.
The graft polymer used in the primer composition of the present invention is obtained by graft polymerizing 15 to 65% by mass of methyl methacrylate on natural rubber. By including such a specific amount of methyl methacrylate in the graft polymer, a pressure-sensitive adhesive tape can be satisfactorily produced regardless of whether the modified NBR-containing primer composition is prepared in either a solvent-based base or a water-dispersed (emulsion-based) base. The adhesion between the film base material and the pressure-sensitive adhesive layer can be improved (see Comparative Examples 5-6 and Examples 1-13).
Furthermore, the primer composition of the present invention contains 100 parts by mass of the graft polymer and 25 to 300 parts by mass of modified NBR, respectively.
Generally, in a pressure-sensitive adhesive tape using a primer composition, the primer is in an intermediate layer between the adhesive layer and the base material layer, and the pressure-sensitive adhesive is peeled off from the adherend. A force relationship of primer <contact between primer and substrate <substrate> is required.
In addition, by including specific amounts of the graft polymer and modified NBR, the primer composition of the present invention has an affinity for both the base material and the adhesive. Therefore, both the base material and the pressure-sensitive adhesive can be firmly connected.
Therefore, since the primer composition of the present invention has a stronger primer binding force and improved adhesion, it is possible to obtain a good pressure-sensitive adhesive tape that satisfies the above-described force relationship.

The modified NBR used in the present invention is blended in order to improve the adhesion between the primer composition, the film substrate of the pressure-sensitive adhesive tape, and the pressure-sensitive adhesive layer. Moreover, it also has an effect of preventing the plasticizer contained in the film base material from moving to the pressure-sensitive adhesive layer.
This is because the modified NBR has a butadiene component having a high affinity for the film substrate and an acrylonitrile component having a high affinity for the pressure-sensitive adhesive layer, and has an affinity for the film substrate and the pressure-sensitive adhesive layer. It is because it has a carboxyl group.
Moreover, the primer composition of the present invention is important for achieving the object of the present invention by blending 25 to 300 parts by mass of the modified NBR with respect to 100 parts by mass (in terms of solid content) of the graft polymer (for example, (See Example 4 and Example 6). The technical significance of this numerical range is that, in the modified NBR 20 parts by mass, the adhesion between the base material and the primer composition and the adhesion after water immersion are insufficient (see Comparative Example 2), and the modified NBR350 It is clear from the parts by mass that the adhesion of the primer composition to the pressure-sensitive adhesive and the adhesion after water immersion are insufficient (see Comparative Example 3).

  That is, the blending amount (in terms of solid content) of the modified NBR in the primer composition is preferably 25 to 300 parts by mass, more preferably 50 to 200 parts by mass, with respect to 100 parts by mass (in terms of solid content) of the graft polymer. 100-200 mass parts is preferable. If the amount of the modified NBR is too small, the adhesion between the primer composition and the film substrate may be weakened. Moreover, when there are too many compounding quantities of modified | denatured NBR, primer composition itself will become too soft and the adhesive tape obtained may delaminate. By making the modified NBR into a specific numerical value range, it is possible to improve the adhesion between the film base of the pressure-sensitive adhesive tape and the pressure-sensitive adhesive layer, and to obtain a pressure-sensitive adhesive tape excellent in water resistance, heat resistance and dry resistance. .

The amount of carboxyl group modification in the carboxyl-modified acrylonitrile butadiene rubber is not particularly limited, but the above-described effects, particularly the primer composition, can be adjusted by adjusting the amount to 0.3 to 7% by mass, more preferably 0.5 to 7% by mass. This is preferable because the effect of improving the adhesion between the adhesive and the film substrate and the effect of suppressing delamination of the pressure-sensitive adhesive tape due to the appropriate hardness of the primer composition itself are increased. Thereby, it becomes possible to improve the adhesiveness of the film base material and adhesive layer of an adhesive tape.
The “carboxyl group modification amount” can be calculated by NMR or the like. More specifically, the AN content obtained from the KN method can be set as an absolute value and calculated using the MMA / Bd ratio calculated from NMR.

The carboxyl-modified acrylonitrile butadiene rubber is not particularly limited, but low nitrile type (nitrile content 24% or less), medium nitrile type (nitrile content 25-30%), medium high nitrile type (nitrile content 31-35%). ), High nitrile type (nitrile content: 36 to 43%), extremely high nitrile type (nitrile content: 43% or more), and the like. Among these, a medium nitrile type, a medium high nitrile type, a high nitrile type, and the like are preferable, and a medium to high nitrile type having a nitrile content of about 27 to 40% is more preferable. These may be used alone or in combination of two or more.
The “nitrile content” can be calculated by NMR (KN method) or the like.

The graft polymer used in the present invention is blended in order to improve the adhesion between the film base of the pressure-sensitive adhesive tape and the pressure-sensitive adhesive layer.
In general, a graft polymer is a kind of random block copolymer, which has a branched structure in which different types of branched polymer chains are bonded to a main polymer chain.
The graft polymer according to the present invention has a natural rubber (polymer) unit and a methyl methacrylate (monomer / polymer) unit in its structure. For example, a state in which a polymer of methyl methacrylate is bonded in a branch shape (comb shape) from a natural rubber polymer (trunk); a state in which a natural rubber polymer is bonded in a branch shape from a polymer (base) of methyl methacrylate; a natural rubber polymer and a natural rubber Examples include a state in which a polymer of methyl methacrylate is interposed between the polymer and the like. Natural rubber may be fragmented, and methyl methacrylate may be a monomer.
The natural rubber unit (component) has high adhesion to the pressure-sensitive adhesive layer, and the methyl methacrylate unit (component) has high adhesion to the film substrate. For this reason, the adhesive force of the film base material of an adhesive tape and an adhesive layer can be improved by mix | blending a graft polymer as one component of a primer composition.

  The ratio of methyl methacrylate in the graft polymer is 15 to 65% by mass of methyl methacrylate in the natural rubber, preferably 15 to 70% by mass, and more preferably 30 to 50% by mass. At this time, the ratio of the natural rubber is preferably 85 to 30% by mass, more preferably 70 to 50% by mass. By making the ratio of the methyl methacrylate in the graft polymer not too small, the adhesion between the methyl methacrylate and the film substrate is deteriorated, and the delamination of the adhesive tape can be suppressed. Moreover, by making the ratio of methyl methacrylate not too large, the primer composition itself is cured and cannot follow the deformation of the film base material, so that delamination of the adhesive tape can be suppressed.

  As the graft polymer, a graft polymer obtained by graft polymerization of methyl methacrylate on natural rubber can be appropriately selected and employed. For example, the graft polymer can be obtained by a known graft polymerization method such as a suspension polymerization method or an emulsion polymerization method. it can. Commercial products having a methyl methacrylate content of 30 to 50% can be used.

Furthermore, the primer composition can be made into an excellent solvent-based primer composition by adjusting the Mooney viscosity of the graft polymer as follows.
Although the Mooney viscosity of the graft polymer is not particularly limited, for example, the Mooney viscosity (MS _{1 + 4} ) of the graft polymer is obtained by kneading (kneading) the graft polymer itself with an open roll, a Banbury mixer, a kneader or the like. Can be reduced.
At this time, the Mooney viscosity of the graft polymer is preferably 70 to 160 under MS _{1 + 4} and 100 ° C., more preferably 80 to 150.
By preventing the Mooney viscosity of the graft polymer from being reduced too much, delamination between the film substrate and the pressure-sensitive adhesive layer can be prevented by the cohesive failure of the resulting primer composition itself. it can. By not keeping the Mooney viscosity too high, it becomes impossible to follow the deformation of the film substrate, and delamination of the adhesive tape can be suppressed.
That is, by adjusting the Mooney viscosity of the graft polymer to the specific range, the adhesion between the film base of the pressure-sensitive adhesive tape and the pressure-sensitive adhesive layer is further improved, and the water resistance, heat resistance, and dry resistance are further improved. An excellent solvent-based primer composition capable of obtaining an adhesive tape can be obtained.

  The Mooney viscosity may be measured according to JIS K 6300. In this invention, the test was performed 3 times and the average value was employ | adopted.

In addition, the primer composition is not adjusted to the Mooney viscosity of the graft polymer, but is further blended with the following surfactant in the graft polymer and modified NBR to obtain an excellent emulsion primer composition. It is possible. In addition, before blending the surfactant, it is desirable that the graft polymer and / or the modified NBR be in an emulsion state for improving stability.
The surfactant used in the present invention is further blended in the primer composition containing the graft polymer in order to improve the wettability of the primer composition with respect to the film substrate and the adhesive layer of the adhesive tape. .
That is, by containing a surfactant, an excellent emulsion-based primer composition capable of improving the adhesion between the film substrate and the primer composition, and the primer composition and the pressure-sensitive adhesive layer is obtained. be able to.

  The type of the surfactant is not particularly limited, and an ordinary anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant, a polymer surfactant, Various things, such as a fluorochemical surfactant and a reactive surfactant, can be used. These surfactants may be used alone or in combination.

Among these surfactants, an anionic surfactant or a nonionic surfactant is preferably used because it does not cause an acid-base reaction with the adhesive layer.
Examples of the anionic surfactant include fatty acid type, alkylbenzene type, sulfate ester type, higher alcohol type and the like, for example, higher fatty acid sodium, sodium alkylsulfonate, sodium alkylbenzenesulfonate, sodium alkyldiphenyl ether disulfonate, and the like. is there.

Among these surfactants, if a nonionic surfactant is used, when the pressure-sensitive adhesive layer is dried at a high temperature during the production of the pressure-sensitive adhesive tape, or when the usage environment of the pressure-sensitive adhesive tape is a high temperature, It is preferable because it is difficult to decompose.
Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene myristyl ether, polyoxyethylene alkylene alkyl ether, polyoxylethylene derivative, polyoxyethylene polyoxypropylene block polymer, sorbitan fatty acid ester, polyoxyethylene Examples include sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene oleic acid ester, polyoxyethylene alkylamine, alkylalkanolamide, polyoxyethylene nonylphenyl ether, and the like.

The addition amount when the surfactant is blended as described above is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass (in terms of solid content) of the graft polymer. Part.
When the addition amount of the surfactant is 0.1 parts by mass or more, the primer composition may not be uniformly applied to the pressure-sensitive adhesive layer without improving the wettability due to the small addition amount. Can be reduced. On the other hand, when the addition amount of the surfactant is 10 parts by mass or less, the primer composition has a plasticizing effect by increasing the addition amount, and the primer is unwound when the obtained adhesive tape is unwound. It is possible to reduce the occurrence of cohesive failure of the composition and delamination of the adhesive tape.

If necessary, the primer composition of the present invention may further contain one or more selected from stabilizers, softeners, anti-aging agents, crosslinking agents, modifiers, and the like. In addition, you may add the said surfactant suitably in the range which does not inhibit the effect of this invention.
And the said primer composition can mix | blend the above-mentioned thing, can mix and dissolve with the solvent of water and / or an organic solvent, and can adjust and obtain solid content concentration and solution viscosity suitably.

  The solid content concentration obtained by diluting the primer composition with water and / or an organic solvent is preferably 1 to 20% by mass, and more preferably 3 to 10% by mass in view of coating properties and coating amount.

  The viscosity of the solution obtained by diluting the primer composition with water and / or an organic solvent is preferably from 1 to 500 MPa · s (BM type viscometer router NO. 1 6 RPM) in view of coating property and coating amount, more preferably 10 ˜230 MPa · s is preferable, and 10 to 100 MPa · s is more preferable.

  The viscosity of the solution was adjusted by leaving the solution obtained by diluting the primer composition at a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5% RH in a constant temperature and humidity chamber for 24 hours, and then using a BM viscometer. NO. 1. Set the number of revolutions to 6 rpm, collect the solution viscosity 1 minute after the start of rotation, conduct the test three times, and adopt the average value.

  When the primer composition is diluted with an organic solvent, examples of the solvent include toluene, hexane, normal hexane, ethyl acetate, and methyl ethyl ketone. These solvents may be used alone or in combination of two or more.

  The pressure-sensitive adhesive tape of the present invention can be obtained by interposing the above-described primer composition between a film base material and a pressure-sensitive adhesive layer laminated on at least one surface of the film base material.

  Although the said film base material is not specifically limited, For example, softening agent 30-60 mass parts and Ca-Zn type composite stabilizer 0.1-5 mass parts with respect to 100 mass parts of polyvinyl chloride with a polymerization degree 700-1300. It is desirable to use a mixture containing the above-mentioned primer composition. Moreover, a coloring agent, an antioxidant, a ultraviolet absorber, a lubricant, a filler, and other additives can be blended with the film base as needed within a range not inhibiting the effects of the present invention.

  The means for forming the film substrate is not particularly limited, and various materials can be used by using various conventional kneading and various mixing devices (single- or twin-screw extruder, roll, Banbury mixer, various kneaders, etc.). It mixes so that a component may disperse | distribute uniformly, shape | molds the said mixture into a film with a calendering machine, and obtains it by slitting to the desired film width. As the roll arrangement method in calendar molding, for example, a known method such as L-type, reverse L-type, and Z-type can be adopted, and the roll temperature is usually set in the range of 150 to 200 ° C, preferably 160 to 190 ° C. . The thickness of the film substrate is not particularly limited and is preferably 40 to 300 μm, more preferably 60 to 200 μm.

  The pressure-sensitive adhesive used for the pressure-sensitive adhesive layer may be a general pressure-sensitive adhesive for a pressure-sensitive adhesive tape, and for example, a solvent-type pressure-sensitive adhesive or an emulsion-type pressure-sensitive adhesive can be used. Furthermore, a tackifier, an anti-aging agent, an ultraviolet absorber, a cross-linking agent, a softening agent, and the like can be blended as necessary.

  The base polymer of the pressure-sensitive adhesive is natural rubber. Other than this, recycled rubber, silicone rubber, isoprene rubber, styrene butadiene rubber, polyisoprene, NBR (low, medium, medium high, high, very high type), styrene-isoprene copolymer, styrene-isoprene-butadiene copolymer, One selected from styrene-butadiene-styrene copolymers, and known graft polymers (eg, Patent Documents 1 and 2) that are also blended in the primer composition, graft polymers such as the above-mentioned graft polymers, and the like. Alternatively, two or more kinds may be added.

Further, the tackifier is not particularly limited. For example, terpene resin, rosin resin, hydrogenated rosin resin, coumarone / indene resin, styrene resin, aliphatic and alicyclic petroleum resins, terpene-phenol, etc. Examples thereof include one or more selected from resins, xylene-based resins, other aliphatic hydrocarbon resins, aromatic hydrocarbon resins, and the like.
Examples of the anti-aging agent include one or two selected from a phenol-based anti-aging agent, an amine-based anti-aging agent, a benzimidazole-based anti-aging agent, a dithiocarbamate-based anti-aging agent, a phosphorus-based anti-aging agent, and the like. More than species.
Moreover, as a crosslinking agent, the 1 type (s) or 2 or more types chosen from an isocyanate type, an epoxy type, an amine type etc. are mentioned, for example.

The blending ratio of each component in the pressure-sensitive adhesive is not particularly limited. For example, 100 parts by weight of natural rubber, 10 to 50 parts by weight of a graft polymer (preferably 20 to 40 parts by weight), and 85 to 135 parts by weight of a tackifier. Parts (preferably 100 to 120 parts by mass) and the like, and an anti-aging agent and an ultraviolet absorber may be appropriately blended.
The solid content concentration of the pressure-sensitive adhesive may be about 15 to 55%, and the viscosity of the pressure-sensitive adhesive is preferably 1 to 50000 MPa · s (BM type viscometer router NO. 4 6 RPM), and more preferably 5000 to 40000 MPa · s is good.

The manufacturing process of the adhesive tape using the said primer composition is demonstrated.
After diluting and dispersing the primer composition with water and / or an organic solvent, a gravure coater, spray coater, kiss roll, bar coater, knife coater, etc. on one side of a film substrate mainly composed of soft polyvinyl chloride Apply and dry. In addition, at this time, the thickness of the primer after drying can be appropriately selected within a range not impairing the effects of the present invention, but it is preferably 1 to 50 μm, more preferably 5 to 30 μm. .
Then, an adhesive is apply | coated and dried on the dried primer composition, an adhesive layer is formed, and it can be set as an adhesive tape.
The means for applying the adhesive is not particularly limited, and a conventional coater such as a roll coater, gravure coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, spray coater, etc. Can be used. Although the thickness of the adhesive layer after drying can be suitably selected in the range which does not impair adhesiveness and handleability, the thickness of an adhesive layer is 5-50 micrometers, for example, Preferably it is 10-30 micrometers. If it is thinner than this, the adhesive force and the unwinding force may decrease. On the other hand, if it is thicker than this, the coating performance may deteriorate.
When winding up the completed adhesive tape, if necessary, a release agent may be laminated on the back surface of the substrate, or a release sheet may be laminated on the adhesive. Moreover, what is necessary is just to perform the coating process of a primer composition and an adhesive also on the back surface, when applying an adhesive to both surfaces of a base material as an adhesive tape.

  In this way, the pressure-sensitive adhesive tape of the present invention can be obtained. Since the pressure-sensitive adhesive tape of the present invention uses the above-described primer composition, the adhesion between the film base of the pressure-sensitive adhesive tape and the pressure-sensitive adhesive layer is improved, and it is also excellent in water resistance, heat resistance, and cold resistance. It is a thing. For this reason, the adhesive tape of the present invention can be expected to be used as an electric wire bundle in the electric / electronic field, the automobile field, and the like.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

  The evaluation result of the adhesive tape which uses each primer composition of Examples 1-13 mentioned later and Comparative Examples 1-6 is shown to Table 1 and 2. FIG.

“Adhesion between the base material and the primer composition” in Tables 1 and 2 indicates that Bencot M-1 (material: cupra) is used as a wear material on a 100 mm long and 50 mm wide film base material on which a primer is laminated. , A weight of a load of 500 g is put on it and reciprocated once to rub the primer and the wear material, and then the fallen state of the primer applied to the film substrate is visually confirmed.
The test environment was an evaluation test chamber set at a temperature of 23 ° C. ± 2 ° C. and a humidity of 50 ± 5% RH, a low temperature chamber set at a temperature of −5 ° C. ± 2 ° C., a temperature of 50 ° C. ± 2 ° C., and a humidity of 80 ± 5 The test was conducted after adjusting the 24 HR condition in an environmental testing machine set to% RH. The average value of the measured values of n = 3 or more was shown, and the primer was not passed even if the test was repeated three times or more.

  “Adhesion between primer composition and adhesive” in Tables 1 and 2 refers to the number of times the adhesive is peeled off from the primer composition and the adhesive is removed from the primer composition. is there. An evaluation test chamber set at a temperature of 23 ° C. ± 2 ° C. and a humidity of 50 ± 5% RH, a low temperature chamber set at a temperature of −5 ° C. ± 2 ° C., and a temperature of 50 ° C. ± 2 ° C. and a humidity of 80 ± 5% RH The test was carried out after adjusting the 24HR condition in the environmental test machine. The average value of the measured values of n = 3 or more was shown, and the adhesive that did not fall out even if the test was repeated three times or more was regarded as acceptable.

  “Adhesiveness after water immersion” in Tables 1 and 2 was obtained by immersing a base film on which a primer was laminated and a pressure-sensitive adhesive tape obtained by laminating a pressure-sensitive adhesive on the substrate film in pure water at 23 ° C. for 24 HR. Thereafter, the water adhering to the primer composition and the pressure-sensitive adhesive surface was wiped off, and after 30 seconds, the above-mentioned “adhesion between the substrate and the primer composition” and “adhesion between the primer composition and the pressure-sensitive adhesive” were performed. It is a thing. The average value of the measured values of n = 3 or more is shown, and the sample in which the primer or the pressure-sensitive adhesive did not fall out even when the test was repeated three times or more was regarded as acceptable.

“Tape unfoldability” in Tables 1 and 2 indicates that the adhesive remains on the back of the film substrate when the adhesive tape is unwound at a tensile speed of 50 m / min using a tensile tester specified in JIS B 7721. It is a thing. The pressure-sensitive adhesive tape to be tested was confirmed to have a tape state of n = 3 or more, and the film base material, the primer composition, the primer composition, and the pressure-sensitive adhesive were not peeled.
In Table 2, the material destruction indicates a case where the film substrate and the primer composition, or the primer composition and the adhesive are peeled off, and the cohesive failure indicates a film in which the adhesive layer itself is a laminate of the primer composition. It shows that it has remained separately on the back surface of the base material and the wound film base material.

Example 1
(A) The film substrate is composed of 45 parts by mass of a softening agent, 1.5 parts by mass of a Ca—Zn composite stabilizer with respect to 100 parts by mass of polyvinyl chloride having a polymerization degree of 1000, a colorant, an ultraviolet absorber, a lubricant, The filler is obtained by using a Banbury mixer to mix the components so that they are uniformly dispersed, and molding the mixture into a film having a thickness of 150 μm using an L-type calendar molding machine.
(B) The primer composition contains 100 parts by mass of “MEGAPOLY 50 (Moony viscosity 150, methyl methacrylate content 49% by mass)” manufactured by GREEN HPSP, as a graft polymer, and “Nipol 1072J (manufactured by Nippon Zeon Co., Ltd.)” The amount of carboxyl modification was 7.0% by mass) ”was obtained by mixing and dissolving 100 parts by mass with toluene and adjusting the solid content concentration to 4% and the solution viscosity to 40 MPa · s. The obtained primer composition was applied to one surface of the film substrate using a gravure coater so that the thickness after drying was 0.7 μm, and dried and laminated.
(C) The pressure-sensitive adhesive is 100 parts by mass of natural rubber (Mooney viscosity 45), 20 parts by mass of graft polymer obtained by graft copolymerization of 30% by mass of methyl methacrylate with 70% by mass of natural rubber, “MEGAPOLY 30 (manufactured by GREEN HPSP) Mooney viscosity 80, methyl methacrylate content 30% by mass) ”, tackifier 100 parts by mass“ YS resin PX-1000 manufactured by Yasuhara Chemical Co., Ltd. ”, and anti-aging agent 2 parts by mass“ Antage W-500 manufactured by Kawaguchi Chemical Industries ” Was dissolved in toluene and adjusted to a solid content concentration of 35% and a viscosity of 30000 MPa · s. The obtained pressure-sensitive adhesive was applied onto the primer composition using a roll coater so that the thickness after drying was 20 μm, and dried to obtain a pressure-sensitive adhesive tape.
Other examples and comparative examples described below are the same as the present example unless otherwise specified.

(Example 2)
In Example 2, a primer composition having a solid content concentration of 6% and a solution viscosity of 230 MPa · s by adjusting the amount of toluene in the primer composition used in Example 1 was used.

Example 3
Example 3 is modified NBR “Nipol 1072J (carboxyl modification amount 7.0 mass%) manufactured by Nippon Zeon Co., Ltd.” which is a component of the primer composition used in Example 1, and “NipolDN631 (carboxyl modification amount 0 manufactured by Nippon Zeon Co., Ltd.)”. .5 mass%), and the primer composition was mixed and dissolved in toluene to obtain a primer composition having a solid content concentration of 4% and a solution viscosity of 65 MPa · s.

Example 4
In Example 4, the compounding amount “100 parts by mass” of the modified NBR that is a component of the primer composition used in Example 1 was changed to “25 parts by mass”, and mixed and dissolved in toluene. A primer composition having a solid content concentration of 4% and a solution viscosity of 100 MPa · s is used.

(Example 5)
In Example 5, the compounding amount “100 parts by mass” of the modified NBR that is a component of the primer composition used in Example 1 was changed to “200 parts by mass”, and mixed and dissolved in toluene. A primer composition having a solid content concentration of 4% and a solution viscosity of 40 MPa · s is used.

(Example 6)
In Example 6, the compounding amount “100 parts by mass” of the modified NBR that is a component of the primer composition used in Example 1 was changed to “300 parts by mass”, and mixed and dissolved in toluene. A primer composition having a solid content concentration of 4% and a solution viscosity of 25 MPa · s is used.

(Example 7)
In Example 7, modified NBR, which is a component of the primer composition used in Example 1, was used as modified NBR used in Example 1 [Nipol 1072J (carboxyl modification amount: 7.0% by mass) manufactured by Nippon Zeon Co., Ltd.]] 50 parts by mass. And modified NBR used in Example 3 [DN631 manufactured by Nippon Zeon Co., Ltd. (carboxyl modified amount: 0.5% by mass)] “50 parts by mass”, mixed and dissolved in toluene, A primer composition having a solid content concentration of 4% and a solution viscosity of 65 MPa · s is used.

(Example 8)
In Example 8, the graft polymer “MEGAPOLY 50 (manufactured by GREEN HPSP) (Mooney viscosity 150, methyl methacrylate content 49% by mass)”, which is a component of the primer composition used in Example 1, was replaced with “MEGAPOLY 30 manufactured by GREEN HPSP”. (Mooney viscosity 80, methyl methacrylate content 30% by mass) "and using a primer composition mixed and dissolved in toluene to obtain a primer composition with a solid content concentration of 4% and a solution viscosity of 35 MPa · s It is.

Example 9
In Example 9, the Mooney viscosity of the graft polymer [MEGAPOLY50 (Mooney viscosity 150, methyl methacrylate content 49 mass%) manufactured by GREEN HPSP Co., Ltd.], which is a component of the primer composition used in Example 1, was kneaded. The primer composition was adjusted to “80” and mixed and dissolved in toluene to obtain a primer composition having a solid content concentration of 4% and a solution viscosity of 40 MPa · s.

(Example 10)
Example 10 is a graft polymer of the primer composition used in Example 1, “MEGAPOLY 50 (Moony viscosity 150, methyl methacrylate content 49% by mass)” manufactured by GREEN HPSP, and modified NBR “manufactured by Nippon Zeon Co., Ltd.” 100 parts by mass of Nipol 1072J (carboxyl modification amount: 7.0% by mass), 100 parts by mass of graft polymer “MG-40 (methyl methacrylate content: 40% by mass)” manufactured by REREGEX, and modified NBR “manufactured by Nippon Zeon Co., Ltd.” Nipol 1571 (carboxyl modification amount: 3.0% by mass) ”was changed to 100 parts by mass. In addition to these graft polymer and modified NBR, as a surfactant,“ PEX SS-H (sodium alkyldiphenyl ether disulfonate) manufactured by Kao Corporation ” "1 part by weight, this compound By mixing and diluting with water, solid content of 10% of the primer composition is obtained by using a primer composition with a solution viscosity of 10 MPa · s.

(Example 11)
In Example 11, 1 part by mass of the surfactant “Perex SS-H (sodium alkyldiphenyl ether disulfonate) manufactured by Kao Corporation” in the primer composition used in Example 10 was replaced with “sodium alkylsulfosuccinate manufactured by Kao Corporation”. The primer composition was changed to 1 part by mass, mixed and diluted with water to obtain a primer composition having a solid content concentration of 10% and a solution viscosity of 10 MPa · s.

(Example 12)
In Example 12, the compounding amount “1 part by mass” of the surfactant that is a component of the primer composition used in Example 10 was changed to “5 parts by mass”, and mixed and diluted with water to obtain a primer composition A primer composition having a solid content concentration of 10% and a solution viscosity of 15 MPa · s is used.

(Example 13)
In Example 13, the compounding amount “1 part by mass” of the surfactant that is a component of the primer composition used in Example 10 was changed to “10 parts by mass”, and mixed and diluted with water to obtain a primer composition A primer composition having a solid content concentration of 10% and a solution viscosity of 20 MPa · s is used.

[Results of Examples 1 to 13]
As shown in Table 1, all the characteristic values were evaluated as good, and the target primer composition and adhesive tape were obtained.

(Comparative Example 1)
In Comparative Example 1, each compound was mixed and dissolved in toluene without adding modified NBR to the primer composition to obtain a primer composition having a solid content concentration of 4% and a solution viscosity of 550 MPa · s. In Comparative Example 1, good evaluation was obtained for “adhesion between the substrate and the primer composition”, “adhesion between the primer composition and the pressure-sensitive adhesive”, “adhesion when immersed in water”, and “tape spreadability”. I couldn't.

(Comparative Example 2)
In Comparative Example 2, the modified NBR, which is a component of the primer composition used in Example 1, was changed to “NBRNipol 1072 (carboxyl modification amount: 0.0% by mass) manufactured by Nippon Zeon Co., Ltd.”, mixed and dissolved in toluene to obtain a primer A primer composition having a solid content concentration of 4% and a solution viscosity of 90 MPa · s is used.
In Comparative Example 2, good evaluation could not be obtained for “adhesion between the primer composition and the pressure-sensitive adhesive”, “adhesion when immersed in water”, and “tape spreadability”.

(Comparative Example 3)
In Comparative Example 3, the compounding amount “25 parts by mass” of the modified NBR that is a component of the primer composition used in Example 1 was changed to “20 parts by mass”, and mixed and dissolved in toluene. A primer composition having a solid content concentration of 4% and a solution viscosity of 150 MPa · s is used. In Comparative Example 3, good evaluation could not be obtained for “adhesiveness between the substrate and the primer composition”, “adhesiveness when immersed in water”, and “tape spreadability”.

(Comparative Example 4)
In Comparative Example 4, the amount of the modified NBR, which is a component of the primer composition used in Example 1, was changed from “25 parts by mass” to “350 parts by mass” and mixed and dissolved in toluene to obtain a solid primer composition. A primer composition having a partial concentration of 4% and a solution viscosity of 20 MPa · s is used.
In Comparative Example 4, good evaluation could not be obtained for “adhesion between the primer composition and the pressure-sensitive adhesive”, “adhesion when immersed in water”, and “tape spreadability”.

(Comparative Example 5)
In Comparative Example 5, a graft polymer “MEGAPOLY 50 (Moony viscosity 150, methyl methacrylate content 49 mass%) manufactured by GREEN HPSP Co., Ltd.” which is a component of the primer composition used in Example 10 was replaced with “MG- 67 (methyl methacrylate content 67% by mass) ”was changed to 100 parts by mass, mixed and diluted with water to use a primer composition having a primer composition solid content concentration of 10% and a solution viscosity of 20 MPa · s. Is.
In Comparative Example 5, good evaluation could not be obtained for “adhesion between the primer composition and the pressure-sensitive adhesive”, “adhesion when immersed in water”, and “tape spreadability”.

(Comparative Example 6)
In Comparative Example 6, the graft polymer “MEGAPOLY50 (Mooney viscosity 150, methyl methacrylate content 49 mass%) manufactured by GREEN HPSP Co., Ltd.” in the primer composition used in Example 10 was replaced with “MG-10 manufactured by Regex Corporation ( (Methyl methacrylate content 10% by mass) ”is changed to 100 parts by mass, mixed and diluted with water, and used a primer composition having a primer composition solid content concentration of 10% and a solution viscosity of 20 MPa · s. is there.
In Comparative Example 6, good evaluation could not be obtained for “adhesion between the base material and the primer composition”, “adhesion when immersed in water”, and “tape spreadability”.

  By using the tape of the present invention, the adhesion between the film substrate of the adhesive tape and the adhesive layer can be improved, and an adhesive tape excellent in water resistance, heat resistance and cold resistance can be obtained. It can be expected to be used for wire bundling in the automotive and automotive fields.

Claims (2)

100 parts by weight (in terms of solid content) of a graft polymer obtained by graft-polymerizing 30-50% by weight of methyl methacrylate on natural rubber, and 25-300 parts by weight of a carboxyl group-modified acrylonitrile butadiene rubber, the carboxyl group-modified acrylonitrile Butadiene rubber has a carboxyl group modification amount of 0.3 to 7% by mass, a solid content concentration diluted with a solvent is 1 to 20% by mass, and the solution diluted with the solvent has a temperature of 23 ± 2 ° C. and a humidity of 50 Whether the grafted polymer has a viscosity of 1 to 500 MPa · s after being allowed to stand in a constant temperature and humidity room for ± 5% RH for 24 hours, and the graft polymer has a Mooney viscosity of 70 to 160 at MS _{1 + 4} and 100 ° C. Or 0.1 to 10 parts by mass of a surfactant (solid) with respect to 100 parts by mass (in terms of solid content) of the graft polymer Minute basis) is obtained by containing the primer composition, soft poly vinyl chloride film substrate to a main material, an adhesive which mainly including natural rubber laminated on at least one surface of the film substrate Adhesive tape obtained by interposing between the layers. The adhesive tape, adhesive tape according to claim 1, characterized in that it is a for electrical insulation.